Fluid pressure regulator

ABSTRACT

A fluid pressure regulator capable of adjustably setting a cut-off pressure between an upper and a lower limit having a two-piece valve body where the two pieces are threadably joined such that adjusting the distance between the two pieces (34, 54) of the valve body moves a piston (12) stem valve operating a high pressure port (40) towards or away from the high pressure port while not changing the distance between a spring (84) engaging the piston (12) and the piston head (14).

FIELD OF THE INVENTION

Fluid pressure regulators, more specifically a fluid pressure regulatorcapable of adjustably selecting a cut-off pressure between an upper anda lower limit.

BACKGROUND

Fluid pressure regulators regulate the flow of fluid between a highpressure port and a low pressure port. Typically, regulators are presetto allow fluid to flow when pressure at a low pressure port drops belowa predetermined upper limit.

One type of pre-set regulator is known as a piston-type regulator. Thisregulator typically comprises a valve body, a hollow stem piston and aspring. When fluid pressure at the low pressure port of the valve bodydrops below a pre-set minimum, a coil spring operating on the undersideof the piston head lifts the piston operated stem valve off the highpressure inlet port to provide fluid flow between the inlet port and theoutlet port. At the same time, some of the fluids flow up the hollowpiston stem to be captured in the cylinder head between the head of thevalve body and piston face. As pressure at the outlet port increases, sodoes back pressure in the cylinder forcing the piston down and thepiston stem valve against the high pressure inlet port.

U.S. Pat. No. 4,924,904 discloses a piston-type pressure regulatorhaving a variable pressure differential adjustability through the use ofa camming plate that can adjustably preload the spring which acts on thepiston body, tending to force the stem of the piston off thehigh-pressure valve seat. This is effected by adjusting the preload onthe spring against the piston and selectively compressing the spring toachieve the desired pressure differential (cut-off pressure) of thepiston stem against the valve seat.

Applicant's invention provides, however, in a unique piston type fluidregulator, the capability of providing in a single regulator a devicecapable of adjustably selecting a cut-off pressure.

SUMMARY OF THE INVENTION

Applicant's invention provides a two-piece valve body which allows thedistance between the face of the piston operated stem valve of thepiston and the high pressure inlet port with which it engages, to beadjustably set. By doing so, the result will be changing the cut-offpressure at the low end port. That is, if the distance between the faceof the stem valve and the high pressure inlet port is increased bythreadably adjusting the two pieces of the valve body, then greaterpressure (the spring would require more linear compression) will berequired to shut off the high pressure port. By decreasing the distancebetween the face of the stem valve and the low end port, less pressurewill be required to seat the stem valve against the high pressure portand cut off the high pressure source.

Applicant's embodiments also include one having a movable inlet portorifice. The purpose of the movable inlet port orifice is to helpmaintain the cut-off pressure at its preset value as the source pressuredrops and fluid in the source bottle is used up. This helps avoid thenecessity of making small adjustments to the valve body to maintain apreset cut-off pressure.

It is, therefore, the object of Applicant's present invention toprovide, in a piston type fluid pressure regulator, a means of randomlyselecting a cut-off pressure between an upper and lower limit byutilizing a two-piece valve body capable of adjustably setting thedistance between a high pressure port and piston operated stem valvewhile maintaining a fixed distance between the spring seat and thepiston.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side elevational cut-away view of the piston of Applicant'spresent invention.

FIG. 2 is a side elevational cut-away view through the center of thefirst valve body of Applicant's present invention.

FIG. 3 is a side elevational cut-away view through the center of thesecond valve body, including cylinder head, of Applicant's presentinvention.

FIG. 4 is a cut-away elevational view of the entire regulator with firstand second valve bodies, piston, spring, piston stem, and port sealingmeans.

FIG. 5 illustrates a cross-sectional elevational view of an alternatepreferred embodiment for Applicant's present invention which includes anexternal connection tube providing fluid communication between the highpressure inlet port and the space between the piston head and thecylinder head.

FIG. 6 is a cross-sectional elevational view through the longitudinalaxis of an alternate preferred embodiment of applicant's presentinvention.

FIG. 7 is a cross-sectional elevational view of an alternate preferredembodiment of applicant's regulator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Perhaps it is most effective to illustrate and discuss the separatepieces of Applicant's present invention at the outset and finish withthe way the pieces fit together into a unitary, functional regulatorfollowed by a brief description of the manner in which the regulatoroperates. With that in mind, we turn now to FIG. 1 which illustrates thepreferred embodiment of piston (12) of Applicant's present invention. Ingeneral, the piston is seen to be not much different than pistons foundin prior art piston regulators. Piston (12) is seen to have cylindricalpiston head (14) with a face or top surface (15) at one end of pistonhead (14). Piston stem (16) is, like head (14) cylindrical and iscoincident with the longitudinal axis of piston (12). It is hollow,having an external diameter less than that of piston head (14). Stem(16) joins underside or bottom of bottom surface (17) of piston head(14) as illustrated in FIG. 1. As stated, stem (16) is hollow having alongitudinal channel (18) along the longitudinal axis thereof extendingfrom a first end (20) at a stem face and a second end (22) open topiston face (15). Piston head (14) has side walls (24) which are notchedor grooved to define a sealing ring groove (26). Likewise, near firstend (20) of channel (18) are walls defining yet another sealing ringgroove (28), the walls of the groove being integral with the wallsdefining the outer surface of stem (16). More details of first end (20)reveal that channel (18) communicates through stem at ports (30).Further, first end (20) of stem (16) is seen to have walls defining anindent portion (32) designed to accommodate a seat, adjacent a stem lip(33). Last, both sealing ring grooves (26) and (28) are dimensioned toaccept sealing rings for fluid sealing relationship with walls as moreparticularly set forth with reference to FIGS. 2 and 3 more particularlybelow.

FIG. 2 illustrates a first valve body (34) having a generally irregularexterior shape. First valve body (34) is comprised of a first threadedportion (36) terminating at shoulder (37) defining, in part, some of theinner walls of the valve body. Adjacent to shoulder (37) are threadedpassageways (51) designed for the receipt of set screws therein. It canbe seen that the inner walls of first valve body (34) also have a secondthreaded portion (38) terminating at a high pressure port (40) and athird threaded portion (41) terminating at low pressure port (42).Auxiliary port (43) provides communication between intermediate chamber(44) and fourth threaded portion (43a). The first threaded portion (36)will receive the second valve body as set forth in more detail withrespect to FIG. 3 below. The second threaded portion (38) is designed toaccept the high pressure fluid vessel connective device. The thirdthreaded portion (41) engages the low pressure source and the fourththreaded portion (43a) engages a pressure gauge to measure pressure inintermediate chamber (44).

A portion of the inner walls of first valve body (34) are dimensioned toprovide a cylindrical intermediate chamber (44) which communicates withthe area outside valve body (34) through both ports (40) and (42).Intermediate chamber (44) is defined by cylindrical inner walls (45).Adjoining cylindrical walls (45) and part of the walls definingintermediate chamber (44) are a lip (46) which encircles one end of highpressure port (40) and base (52) from which lip (46) projects. It isfurther seen in FIG. 2 how cylindrical inner walls (45) make up, inpart, a portion of stem receiving member (48) which is also defined, inpart, by stem receiving member walls (50). The function of the structureof first valve body (34) and the details related with the discussion ofFIG. 2 set forth herein above will become more apparent with referenceto FIG. 5 below.

FIG. 3 illustrates a second valve body (54) having an outer surfacedefined in part by a first threaded portion (56) and having an innersurface defined in part by a second threaded portion (58). The innersurface also has walls defining spring chamber (60) dimensioned forreceipt of a spring therein. A shoulder (62) separates second threadedportion (58) from spring chamber (60). A partition (64) at the base ofspring chamber (60) provides a support base for a coil spring or otherbias means and terminates at stem bore (66) dimensioned for receipt ofstem (16) therethrough. Annular gap (68) is provided in the outer wallsof second valve body (54) for engagement with set screws as moreparticularly described with reference to FIG. 4 below. Annular gap (68)is defined in part by wall (69) and at one end by shoulder (70). Aninner wall portion (72) of second valve body (54) is designed forreceipt of stem receiving member (48) therein, as noted by thesimilarity between their shapes. Relief port (57) is provided tomaintain ambient pressure in spring chamber (66).

FIG. 3 also illustrates a cylinder head (74) having outer walls (76)which include a threaded portion (78) and having inner walls (80) whichare cylindrically shaped and dimensioned to slidably accept the pistonhead (14) therein. Cylinder head (74) is screwed into second valve body(54) such that threaded portion (78) engages second threaded portion(58) of second valve body (54), and becoming an integral part of secondvalve body, hereinafter referred to as the second valve body.

With reference to FIG. 4, it is seen that piston (12) is inserted withcoil or disk spring (84) over stem (16) with first valve body (34)threadably engaged to second valve body (54). More particularly, firstthreaded portion (36) of first valve body (34) engages first threadedportion (56) of second valve body (54). Stem face (20) is adjacent seat(86) to contact high pressure port (40) at lip (46). Seat (86) istypically cylindrically shaped and comprised of a durable, non-metallicmaterial, such as Teflon. In operation, typically seat (86) will contactlip (46) of high pressure port (40). At this point, spring (84) hascontacted at a first end, underside or bottom surface (17) of pistonhead (14) and at the other end is seated against partition (64).

FIG. 4 also illustrates the manner in which set screws (88) aretypically and preferably in close proximity to the wall (69) of annulargap (68) and, in conjunction with shoulder (70), act as a means to lockthe two valve bodies together to prevent unintended uncoupling. Morespecifically, FIG. 4 illustrates the use of set screws 88 which, whenthreaded through the walls of first valve body (34) such that they arepreferably locked in close proximity to the wall (69) of annular gap(68), can prevent, by interference with shoulder (70), the two valvebodies from separating. As set forth above with reference to thepreceding figures, sealing means are required at grooves (26) and (28).FIG. 4 illustrates the use of "O" rings (90) and (92) to effect asubstantially fluid-tight seal. Thus, it is important for the set screwsand shoulder to be situated such that they engage one another before thethreads engaging the two valve bodies disengage.

In operation, the two valve bodies are threaded together until the valvestem comes into proximity of the high pressure port and then adjusted sothat fluid at the high pressure port may flow into the intermediatechamber. The high pressure fluid source is connected to the secondthreaded portion and the low pressure vessel is threaded to the thirdthreaded portion of the first valve body. The fourth threaded portionwill typically provide a gauge for measuring pressure in theintermediate chamber. With the gauges and vessels attached to the firstvalve body in fluid sealing relation, the high pressure source is ventedto the high pressure port which will fill the intermediate chamber andgo up the channel in the piston stem to act on the piston face and drivethe piston down to seat the high pressure valve when pressure in theintermediate chamber, generated at the low pressure port drives thepiston head and stem valve against the high pressure port. A suitablegauge located in the fourth threaded portion will measure the pressureat which such cut-off occurs. The user may then adjustably increase ordecrease that cut-off pressure, changing the distance between the twovalve bodies by holding one valve body while rotating the other. Movingthe stem valve away from the high pressure port will increase thecut-off pressure, moving it towards the high pressure port will decreasethe cut-off pressure. By adjustably locating this distance whilewatching the intermediate chamber gauge (not shown), the user mayadjustably set the cut-off pressure desired.

FIG. 5 illustrates another alternate preferred embodiment of Applicant'sinvention. More specifically, FIG. 5 illustrates first valve body (34)and second valve body (54) containing therein piston (12) having a solidstem (16A) instead of the hollow stem (16) as provided for in theembodiments illustrated above. Having a solid stem, fluideouscommunication must be provided by another means to the region betweentop surface (15) of piston (12) and cylinder head (74A). This is done bymodifying the cylinder head of previous embodiments in the manner setforth in FIG. 5 with reference to element (74A). Here, port (104) offirst valve body (34) is connected to cylinder head (74A) through use ofconnection means (102), such as a tube. Connection means (102) isconnected to cylinder head (74A) through modifications includingcylinder head port (98). Engagement means (100) engageable with stemportion (96) of cylinder head (74A) provides ready connection betweenconnection means (102), here simply a fluid-tight external connectiontube made of brass, copper, or other suitable material. Fluid entershigh pressure port (42) which is open to first chamber (106). Aspressure at port (104) drops below cutoff, seat (86) will lift off lip(46), allowing fluid from first chamber (106) to flow through ports(104) and (40) until back pressure at port (40) is sufficient to urgepiston (12) with seat (86) against lip (46).

FIG. 5 is also used to illustrate the use of bias means (94) forpreloading piston (12) for urging towards low pressure port (40). Biasmeans (94) here is a spring steel cylindrical washer. Applicant hasfound that providing a preloading condition such as bias means (94)produces increased sensitivity of cutoff pressure adjustment byovercoming required sealing pressure at the high pressure inlet port,especially when providing a cut-off pressure in the ranges from 0 up toabout 60 pounds per square inch. Use of bias means (94), of course, canbe provided with all embodiments illustrated earlier, not just theembodiment illustrated in FIG. 5.

FIG. 6 includes another preferred embodiment of applicant's pressureregulator. FIG. 6 provides for a movable high-pressure inlet orifice(110). Movable high-pressure inlet orifice (110) is part of a tube (112)slideably engaged to the walls (114) of the high-pressure inlet port(40). Tube (112), having movable orifice (110) at a first end locatedwithin intermediate chamber (44), has a removed second end (116) exposedto the high-pressure fluid, the subject of which is regulated. "O" ringor other sealing means (118) maintains a fluid sealing relation betweenoutside walls (120) of the tube (112), preventing fluid leakage betweenhigh-pressure fluid source and intermediate chamber (44). Spring (122)retained in spring chamber (123) by plate (124) which is held to tube(112) near the second end by clip (126) prevents high-pressure fluidfrom forcing tube (112) through port (40). However, as the high-pressuresource drops off, spring (122) will tend to move orifice (110) and tube(112) away from first end (20) of stem (16), requiring additional linearcompression on spring (84) to cut off pressure at the preselectedcut-off pressure.

Use of the spring-biased, movable seat helps prevent the drop off ofoutlet pressure cut-off while inlet pressure (source) drops. Forexample, if a 3000 psi source issued and cut-off pressure initially isset at 150 psi, as the source pressure drops cut-off pressure dropsalso, so that, for example, when the source bottle is only 1500 psi,cut-off may occur at, say, 130 psi rather than preset 150 psi. Withoutthe movable seat feature, slight readjustment of the valve bodies wouldbe required by moving the seat farther from the stem and resetting the150 psi cut-off pressure. This is the result, in part, of frictionalforces of the piston against the walls on which it slides and thediminishing of high-pressure fluid working in conjunction with spring(84) to unseat the piston stem.

In any case, high pressure will urge tube (112) against spring (122)causing some compression and moving seat (86) towards first end (110).sah

When the two valve bodies are adjusted to a cut-off pressure of, say,500 psi and the fluid pressure is 3000 psi then, when there is a dropoff in the intermediate chamber to below 500 psi, spring (84) will movethe stem away from seat (86) and allow high-pressure fluid into theinner chamber until the 500 psi is again met. In the fixed inletembodiment (see FIGS. 4 and 5), when the fluid pressure source drops to,say, 1000 psi, then the outlet drops below the 500 psi cut-off becauseof less sealing force required to close the valve. However, with themovable inlet design, spring (84) is forced to compress more (by buildupof pressure at outlet) as movable inlet orifice (110) actually movesaway from stem (20) under urging of spring (122).

FIG. 6 also includes an automatic bleed down feature. "O" rings (92)provide a seal against the walls of the inner chamber and the pistonstem. Further, it can be seen in FIG. 6 that, where walls of the innerchamber meet the end of the piston stem, they are canted outward atwalls portions (130). Thus, when the "O" rings meet leading edge (132)of canted walls portion (130), the integrity of the seal is compromisedand fluid in the inner chamber can leak past the "O" rings into spring(88) chamber and out relief port (57). This feature serves two purposes.First, it allows a bleed down of first chamber pressure while regulatoroutput pressure is being adjustably lowered. Second, it allows emergencypressure relief in the event of malfunction or structural failure byallowing blowout through relief port (57) from the inner chamber.

For the bleed down feature, the following example is offered. While theuser attempts to decrease the outlet pressure from, say, 600 psi to 300psi, he will be threading the two valve bodies so piston seat is pressedagainst inlet orifice (110). Adjustment will continue while the userhears a "hiss" of escaping fluids from relief port (57). The outletfluid pressure will be adjusted to drop below the desired 300 psisetting. "O" ring (92) will then reset with spring (84). The user willthen adjust up to the desired 300 psi outlet cut-off pressure.

FIG. 7 illustrates a means for providing bleed down capabilities as apreferred alternative embodiment to that discussed in FIG. 6. Thisembodiment includes a sliding stem receiving member (134), typicallycylindrical, for enclosure within the walls of the first chamber.Sliding stem receiving member (134) slideably engages along inner wallsthereof, the walls of piston stem (16) in fluid sealing relation at "O"rings (92) at a first end of the sliding stem receiving member (134). Ata second end of the sliding stem receiving member (134), it engages thefirst end of movable tube (112). Two springs act on sliding stemreceiving member (134). First sliding stem receiving member spring (136)engages the first chamber walls adjacent high pressure port (40) forurging sliding stem receiving member (134) away from high pressure port(40). Second sliding stem receiving member spring (138) engages plate(140) adjacent and attached to movable tube (112) between the first andsecond ends thereof and also engages the second end of sliding stemreceiving member (134) to urge outer walls of the first end of movabletube (112) against the inner walls second end of the sliding stemreceiving member (134) at lip (142) of inlet orifice (110). Ports (144)provide fluid communication between the inner and outer walls of thesliding stem receiving member (134). "O" ring (146) provides a fluidsealing relation between shoulder (148) on outer walls of the slidingstem receiving member and lip (150) on walls of first chamber (106),under bias of first sliding stem receiving member spring (136).

Bleed down is accomplished by threading the two valve bodies towards oneanother. When seat (86) engages movable inlet orifice (110) furtherthreading will break the seal at "O" ring (146) as shoulder (148) movesaway from lip (150), allowing fluid from the first chamber to escape thefirst chamber through the spring chamber and out relief port (57). Asbefore, threading will be adjusted back and forth until the new, lowerdesired cut-off pressure is reached.

Terms such as "left", "right", "up", "down", "bottom", "top", "front","back", "in", "out" and the like are applicable to the embodiment shownand described in conjunction with the drawings. These terms are merelyfor the purposes of description and do not necessarily apply to theposition or manner in which the invention may be constructed or used.

Although the invention has been described in connection with thepreferred embodiment, it is not intended to limit the invention to aparticular form set forth, but on the contrary, it is intended to coversuch alternatives, modifications, and equivalents as may be includedwithin the spirit and the scope of the invention as defined by theappended claims.

We claim:
 1. A fluid pressure regulator for engaging a high-pressurefluid source comprising:a regulator housing having a high-pressure inletfluid port and a low-pressure outlet fluid port and a chamber allowingfluid communication between said inlet fluid port and said outlet fluidport; a piston having a piston body and a stem, said piston slidabletowards and away from said inlet fluid port in response to fluidpressure in said chamber, said piston capable of seating against saidinlet fluid port; a first spring engageable with said piston for urgingsaid piston away from said inlet fluid port; a first valve body and asecond valve body and wherein said first valve body includes wallsdefining said inlet fluid port and said outlet fluid port and whereinsaid second valve body includes walls in fluid sealing relation withsaid piston body, and wherein said first spring engages walls of saidsecond valve body and said piston body to urge said piston away from theinlet fluid port of said first valve body: and a movable tube forengaging the walls of the chamber, said movable tube including a firstopening in communication with the high-pressure fluid source and asecond opening in communication with said chamber: and a second springcooperating with said movable tube for moving said moveable tube awayfrom the stem face of said piston stem.
 2. The fluid pressure regulatorof claim 1 further including a second spring for urging said pistontowards said inlet fluid port.
 3. The fluid pressure regulator of claim1, further including adjustment means for dynamic external adjustmentallowing the user to select and preset the distance between the firstspring and the inlet fluid port, wherein the external adjustment allowsthe user to set the outlet fluid pressure.
 4. The fluid pressureregulator of claim 3, wherein said adjustment means further compriseswalls integral with the first valve body and walls integral with thesecond valve body, the walls capable of being threadably engaged.
 5. Thefluid pressure regulator of claim 1 further comprising means toreleasably lock said first valve body to said second valve body.
 6. Thefluid pressure regulator of claim 1, wherein said piston includes wallsdefining a channel through the piston stem and piston body.
 7. The fluidpressure regulator of claim 1, wherein said movable tube is axiallyaligned with said piston stem for engaging the stem face of said pistonstem.
 8. The fluid pressure regulator of claim 1 furthercomprising:means cooperating with said piston for relieving pressurefrom the chamber of the valve housing in response to movement of thepiston.
 9. A fluid pressure regulator comprising:a piston having apiston body, including a piston body, piston face and a stem, saidpiston slideable towards and away from said inlet fluid port in responseto fluid pressure in said chamber, said piston capable of seatingagainst said fluid inlet port; a regulator housing having a highpressure inlet fluid port and a low pressure outlet fluid port and achamber allowing fluid communication between said inlet fluid port andsaid outlet fluid port and walls defining a piston chamber for engagingsaid piston; a first spring engageable with said piston for urging saidpiston away from said inlet fluid port; and means responsive to thepressure of the high pressure fluid source for moving said inlet fluidport away from the stem of the piston as the pressure of the highpressure source decreases.
 10. The fluid pressure regulator of claim 9further including means providing fluid communication between saidchamber and said piston chamber such that fluid pressure in said chamberalso acts on the piston face of said piston.
 11. The fluid pressureregulator of claim 9 further including:fluid pressure relief vent; andmeans responsive to relative movement of piston stem towards the inletfluid port for venting fluid pressure from said chamber through saidfluid pressure relief vent.
 12. The fluid pressure regulator of claim 9wherein the regulator housing has a first body part and a second bodypart, the first body part including the piston chamber and the wallsengaging the first spring and the second body part including wallsdefining the chamber, and further including means to adjust the positionof the first body part relative to the second body part.
 13. The fluidpressure regulator of claim 9 further including;means providing fluidcommunication between said chamber and said piston chamber such thatfluid pressure in said chamber also acts on the piston face of saidpiston; and means responsive to relative movement of piston stem towardsthe inlet fluid port for venting fluid pressure from said chamberthrough said fluid pressure relief vent; and wherein the regulatorhousing has a first body part and a second body part, the first bodypart including the piston chamber and the walls engaging the firstspring and the second body part including walls defining the chamber,and further including means to adjust the position of the first bodypart relative to the second body part.